Main beam for a rowing machine



FIG. 1 is a perspective view of a main beam for a rowing machine showing my new design;

FIG. 2 is a right side elevational view thereof, the side opposite being a mirror image;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevational view thereof, the side opposite being a mirror image; and,

FIG. 5 is a bottom plan view thereof.

The broken lines shown in FIG. 1 represent environment only. Portions of FIGS. 3, 4 and 5 have been shown in fragment for ease of illustration. 

The ornamental design for a main beam for a rowing machine, as shown and described. 